William griffith



. UNITED STATES PATENT OFFICE.

\VILLIAM GRIFFITH, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO HIllL SELF AND JAMES C. GRAY, OF SAME PLACE.

PROCESS OF PURlFYING MOLTEN IRON.

SPECIFICATION forming part of Letters Patent No. 289,088, dated November 2'7, 1883.

Application filed May 25, 1883. (No specimens.)

To all whom it may concern.-

The amount of carbonate of potassium and Be it known thatl, IVILLIAM GRIFFITH, of iodide of potassium to be added to the metal Pifiisburg, in the count of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Processes for Purifying Molten Iron; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to an improvement in the manufacture of iron and steel; and it con sists in treating the molten metal with carbonate of potassium and iodide of potassium in order to refine it and to remove impurities therefrom. These chemicals may be added or introduced into the molten metal after it has been run from the furnace into the ladle or Bessemer converters, puddling, refining, openhearth, cupola, blast, and other furnaces.

'I will now describe my invention, so that others skilled in the art may use the same.

hen the metal has been reduced to a molten state in the furnace, carbonate of potassium and iodide of potassium-equal parts of each are added thereto. These chemicals unite with the impurities and rise to the surface with the slag, leaving the refined and purified metal free to be drawn from the furnace. In the puddling-furnace the chemicals should be added to the metal while it is still boiling and before it comes to nature.

In order that the chemicals may actproperly, care should be taken to place them beneath the surface of the molten metal. This may be easily accomplished by inclosing them in thin metal cases or boxes.

Instead of introducing the carbonate of potassium and iodide of potassium into the furnace, they may be placed in the ladle, mold, or Bessemer converter before the molten metal is poured therein.

depends upon the quality of the iron or steel and the amount of impurities, phosphorus, and other foreign substances contained therein; but for ordinary grades of metal forty-five ounces of carbonate of potassium and a like quantity of iodide of potassium may be used with each ton of metal. 7 r

The advantages of my invention are that the phosphorus and other foreign substances are removed from the metal, and it is therefore tough and fibrous throughout, and asuperior quality of manufactured iron or steel may be produced from an inferior quality of metal.

I am aware that both iodide of potassium and carbonate of potassium have heretofore been used separately and each as a component part of some physio for the purification of iron and steel, and do not broadly claim the same; but I am not aware that a compound contain ing only the said two ingredients has hereto fore been employed in manner as herein specified. Therefore,

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s

The processherein described for refining and purifying iron and steel, which consists in sub jecting the molten metal to the action of a compound consisting of the two ingredients, can bonate of potassium and iodide of potassium, in substantially the proportions specified, as and for the purposes set forth.

In testimony whereof I have hereunto set my hand this 19th day of May, A. D. 1883.

\VILLIAM GRIFFITH.

"Witnesses XV. BHCORXVIN, J. K. BAKEWELL. 

